Easy opening can end with nonremovable tab

ABSTRACT

An easy opening container wall comprising a container wall of sheet material, a line of weakness in said container wall at least partially defining a tear portion, a tab having an attachment portion joined to a lever portion for pivotal movement of the lever portion relative to the attachment portion. The lever portion has a rupturing section and the attachment portion is attached to the container wall outside of the tear portion on opposite sides thereof with the rupturing section overlying a region of the tear portion. Pivotal movement of the lever portion causes the rupturing section to bear on the tear portion and rupture the line of weakness. Further pivotal movement of the tab folds the tear portion inwardly to form an opening in the container wall without removing the tab or the tear portion from the container wall.

United States Patent [191 Brown [4 1 May Lt973 EASY OPENING CAN END WITH NONREMOVABLE TAB [75] Inventor: Omar L. Brown, Dayton, Ohio 731 Assignee: Erma] c. Fraze, Dayton, Ohio [22] Filed: May 10, 1971 [21] Appl.No.: 141,509

Primary ExaminerGeorge T. Hall Att0rney-Smyth, Roston & Pavitt [57] ABSTRACT An easy opening container wall comprising a container wall of sheet material, a line of weakness in said container wall at least partially defining a tear portion, a tab having an attachment portion joined to a lever portion for pivotal movement of the lever portion relative to the attachment portion. The lever portion has a rupturing section-and the attachment portion is attached to the container wall outside of the tear portion on opposite sides thereof with the rupturing section overlying a region of the tear portion. Pivotal movement of the lever portion causes the rupturing section to bear on the tear portion and rupture the line of weakness. Further pivotal movement of the tab folds the tear portion inwardly to form an opening in the container wall without removing the tab or the tear portion from the container wall.

14 Claims, 8 Drawing Figures PATENTEDMY 191% 3', 7:30.379

' sum 1 [IF 2 INVfNTOH: Omar L Brown A rroquers PATEHTEUHAY H913 3 730,379

. SHEET 2 OF 2 (MENTOR: Omar Brown EASY OPENING CAN END WITll-li NONREMOVABLE TAB BACKGROUND OF THE INVENTION The typical easy opening container has a tear portion and a tab secured directly to the tear portion so that upon lifting the tab, the tear portion and tab are completely removed from the container wall. The tab and tear portion are relatively small and are frequently carelessly discarded following their removal from the container. The container may also be discarded when empty; however, because the container is relatively large, it can be easily collected for disposal. On the other hand, the tabs and tear portions, being quite small, are much more difficult to collect. Consequently, the separated tabs and tear portions are 1 creating a litter problem particularly at recreational areas.

It has been proposed to solve this problem by providing an easy opening container in which the tab and tear portion are not separable from the container. There are a few easy opening devices which have nonseparablc tabs and tear portions. One kind of such easy opening container uses a tab which forces a tear portion inwardly. U.S. Pat. No. 3,446,389 shows an easy opening container of this type. This invention is directed to certain improvements in an easy opening container of the type shown in this patent.

SUMMARY OF THE INVENTION One feature of the present invention is to provide an easy opening container wall having a nonseparable tab and tear portion in which the tab is attached to the container wall on opposite sides of the tear portion rather than in a conventional fashion on only one side of the tear portion. This produces several advantages.

First, the use of dual attachment points on opposite sides of the tear portion provides greater flexibility in orienting the tab relative to the tear portion. Second, the tab can be located to assure more complete folding of the tear portion inwardly to provide an opening of the desired area. Third, the dual attachment points positively prevent pivotal movement of the tab relative to the container wall in a plane parallel to the container.

The tear portion or panel is formed by one or more rupturable lines of weakness and one or more bendable lines of weakness. The rupturable line of weakness is ruptured by the tab, and the tab then bends the tear portion or panel inwardly to form the opening. In a preferred form of the invention, there are three rupturable lines of weakness substantially intersecting at a region or point with the outer ends of the three rupturable lines being joined by two bend lines.

To obtain mechanical advantage, the tab is of the lever type and includes a lever portion and an attachment portion joined together for pivotal movement of the lever portion about a hinge relative to the attachment portion.'The lever portion has a lifting end and a rupturing region on opposite sides of the hinge. The hinge extends across the tear portion. For maximum mechanical advantage, the distance between the hinge and the lifting end' should be greater than the distance between the hinge and the rupturing region. On the other hand, to obtain adequate folding of the panel inwardly, the distance between the hinge and the rupturing region must be maintained at no less than a prescribed minimum distance. Accordingly, it is necessary to find an optimum compromise for these competing parameters. This is facilitated by the tab of this invention with the dual attachment locations on opposite sides of the tear portion.

Another feature of the invention is that the tab can be oriented so that the rupturing region overlies the region of intersection. When the lever portion is pivoted about the hinge, the rupturing region is forced downwardly against the region of the intersection to initiate severance of the rupturable lines of weakness. This orientation minimizes the force required to initiate severance. Continued pivotal movement of the lever portion rapidly results in substantially complete severance of the rupturable line of weakness.

The invention can best be understood by reference to the following description taken in connection with the accompanying illustrative drawing.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan view of an easy opening container wall constructed in accordance with the teachings of this invention.

FIG. 2 is a top plan view of the container wall with the tab removed and the rivet unstaked.

FIG. 3 is an enlarged, fragmentary sectional view taken generally along line 3-3 of FIG. 2 and'showing the can end attached to a container body.

FIG. 4 is a sectional view taken generally along line 4-4 of FIG. 1.

FIG. 5 is a sectional view similar to FIG. 4 with the lifting end of the tab raised to initiate severance of the rupturable score line.

FIG. 6 is an enlarged, fragmentary sectional view taken along line 6-6 of FIG. 1.

FIG. 7 is a top plan view of the container wall after the tab has been pivoted to fully form an opening in the container wall.

FIG. 8 is a sectional view taken generally along line I 8--8 of FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numeral '11 designates an easy opening container wall in the form of a can end constructed in accordance with the teachings of this invention. The easy opening container wall 11 includes a container wall in the form of a can end 12 constructed of sheet material such as an aluminum alloy and having a peripheral flange 13 for use in attaching the can end to a container body 14 (FIG. 3). The can end 12 has a generally planar region 15 in which a tear portion or inwardly bendable wall region 17 is formed. A tab 19 is secured to the container wall closely adjacent, but outside of the Wall region 17.

Although the inwardly bendable wall region 17 may take many formed, in the embodiment illustrated, it comprises two inwardly bendable wall segments 21 and 23. As best seen in FIGS. 1 and 2, the wall segments 21 and 23 are defined by three rupturable lines of weakness 25, 27 and 29, which extend radially outwardly from a region of intersection 31, and by two hinge or bend lines 33 and 35 which interconnect the extremities of the three rupturable score lines. The rupturable lines of weakness 25, 27 and 29 substantially intersect at the region of the intersection. The rupturable lines 25 and 27 and the bend line 33 form a right triangle and the rupturable lines 25 and 29 and the bend line 35 form an identical right triangle. The rupturable line 25 is common to both of these right triangles. Although each of the wall segments 21 and 23 forms a right triangle, other configurations may be employed. The bend lines 33 and 35 intersect or substantially intersect the rupturable lines which they interconnect.

The bend lines 33 and 35 are preferably formed in a coining operation and the rupturable lines 25, 27 and 29 are preferably formed by a suitable coining and scoring operation. FIG. 3 shows how the rupturable line 25 and the bend line 35 are formed with such formation procedure being typical. The bend line 35 is formed in a coining operation by a punch 36 and a die 36a which cooperate to coin and thin the sheet material along the full length of the bend line 35 to define a bendable web 37. Specifically, a region of the sheet material between the punch 36 and the die 36a is squeezed and thinned thereby causing flow of metal outwardly away from the bendable web 37 In addition, the bendable web 37 is depressed downwardly from the plane of the can end 12 into the cavity of the die 36a by the punch 36. The bendable web 37 generally conforms to the working surfaces of the punch 36 and the die 36a.

A rupturable web 38 which is coextensive with and defines the rupturable line 25 is formed in a two-step operation. First, a relatively thick web 39 is formed in a coining operation by a pair of tools which may be identical to the punch 36 and the die 36a. Accordingly, following the coining operation, the web 39 may be identical to the bendable web 37.

Second, a punch 40 and a die 40a are advanced toward each other to score a central region of the web 39 to thereby define the rupturable web 39. As shown in FIG. 3, the rupturable web 38 is of substantially lesser thickness than the bendable web 37. If desired, ribs and/or panel forming may be employed to soak up the excess metal produced during the coining and scoring operations.

By forming of the bendable web 37 in the coining operation described above, the bendable web is less likely to rupture when the wall segments 21 and 23 are folded inwardly. The can end 12 has a seal coat 41 on the inner surface thereof. By forming the rupturable web 38 in the two-step operation described hereinabove, rupture of the seal coat 41 on the inner face of the can end 12 is less likely to occur.

The tab 19 is constructed of a single piece of sheet material of sufficient strength to rupture the score lines 25, 27 and 29 and to bend the wall segments 21 and 23 formed thereby inwardly the desired amount. The tab 19 has a pair of attachment sections or ears 45 and 47 which collectively form an attachment portion for the tab. The tab also has a lever portion 49 integrally joined to the attachment sections 45 and 47 along a hinge line or bend line 51. The attachment sections 45 and 47 have apertures therein for receiving rivets 53 and 55., respectively, formed integrally with the sheet material of the can end 12.

The lever portion 49 is joined to the attachment portions 45 and 47 by connecting walls 57 and 59, respectively. The sheet material of the tab 19 at and/or adjacent the connecting walls 57 and 59 is sufficiently pliable to form the hinge 51, and therefore, the hinge line extends across the tab adjacent or through the connecting walls. As shown in FIG. 2, the connecting wall 57 slopes downwardly from the lever portion 49 to the attaching section 45 and the connecting wall 59 is similarly sloped.

A marginal portion of the sheet material of the lever portion 49 is turned inwardly to define a peripheral reinforcing bead 61 which extends around the periphery of the tab 19 from the connecting wall 57 to the connecting wall 59 to stiffen the lever portion longitudinally and transversely. The lever portion 49 includes a lifting end 63 and a nose 65. The nose 65 terminates in a rupturing region 67. As shown in FIG. 4, the rupturing region 67 is in the form of a downwardly facing relatively narrow rupturing finger or flange. The nose 65 is stiffened by a peripheral bead 69 which is interrupted at the rupturing region 67 to permit formation of the flange.

As shown in FIG. 1, the rivets 53 and 55 are formed on opposite sides of the tear portion 17. Accordingly, the attachment sections 45 and 47 straddle the tear portion 17. The rupturing region 67 overlies the region of intersection 31 and the lifting end 63 projects toward the periphery of the can end 12. In the embodiment illustrated, the region'of intersection 31 lies substantially at the center of the can end 12; however, this orientation is not essential. The hinge 51 extends across the tear portion 17 and substantial portions of the tear portion lie on both sides of the hinge 51.

In operation of the easy opening container wall 11, the lifting end 63 of the tab 19 is moved away from the can end 12. This causes the lever portion 49 to pivot about the hinge 51 thereby urging the rupturing region 67 against the can end 12 substantially at the region of intersection 31 to apply a concentrated rupturing force thereto. The region of intersection 31 is the location at which severance of the sheet material of the can end 12 is most easily begun. Upon continued pivotal movement of the lever portion 49, the rupturable score lines 25, 27 and 29 are severed beginning at the point of intersection 31 and extending radially outwardly therefrom.

The next phase of the opening operation involves the inward folding of the wall segments 21 and 23 about their respective bend lines 33 and 35. Although some folding action of the wall segments 21 and 23 is in herent in the application of force to cause rupture of the rupturable score lines 25, 27 and 29, the primary folding effect is obtained following such rupture. This delay in the folding action or sequencing of the rupturing and folding action is highly desirable in order to minimize the forces required to accomplish these actions.

Upon continued pivotal movement of the lever portion 49 about the hinge 51, the head 69 of the nose 65 engages and cams the wall segments 21 and 23 inwardly about their respective bend lines 33 and 35. The shape of the periphery of the nose 65 controls the camming action. The degree of inward folding of the wall segments 21 and 23 can be varied by varying the amount of pivotal movement of the lever portion 49 with the degree of bending increasing with an increase in the arc of travel throughwhich the lever portion moves.

By locating the attachment sections 45 and 47 on opposite sides of the tear portion 17, substantial flexibility in tab construction and orientation is achieved. For example, the relative dimensions of the tab 19 could be changed so that the perpendicular distance between the hinge' 51 and the rupturing region 67 would be decreased without moving the rupturing region 67 away from the region of intersection.

Although exemplary embodiments of the invention have been shown and described, many changes, modifications, and substitutions may be made by one having ordinary skill in the art without necessarily departing from the spirit and scope of this invention.

I claim:

1. An easy opening container wall comprising:

a container wall of sheet material;

a line of weakness in said container wall at least partially defining a tear portion;

a tab having an attachment portion joined to a lever portion for pivotal movement of the lever portion relative to the attachment portion, said lever portion having a rupturing section; and

means for fixedly attaching said attachment portion to said container wall outside of said tear portion at first and second locations, said'locations being on opposite sides of said tear portion,said rupturing section substantially overlying a region of said tear portion so that pivotal movement of the lever portion causes the rupturing section to bear on the tear portion and rupture said line of weakness.

2. An easy opening container wall as defined in claim 1 wherein said lever portion is connected to said attachment portion along a hinge line and said hinge line extends across the tear portion.

3. An easy opening container wall as defined in claim 1 wherein said attachment portion includes first and second spaced attachment ears at said first and second locations, respectively.

4. An easy opening container wall as defined in claim 1 wherein said rupturing section terminates in a rupturing point, said line of weakness includes first and second rupturable sections substantially intersecting at a point of intersection, and said rupturing point substantially overlies said point of intersection.

5. An easy opening container wall comprising:

a container wall of sheet material;

a line of weakness in said container wall at least partially defining a tear portion;

a tab having an attachment portion and a lever portion joined together for pivotal movement of the lever portion relative to said attachment portion about a hinge, said lever portion having a rupturing section adapted to engage the tear portion and apply a force thereto; and

means for fixedly attaching said tab to said container wall outside of said tear portion with said hinge extending across a substantial segment of said tear portion, substantial segments of said tear portion lying on opposite sides of said hinge.

6. A tab of the type attachable to a container wall comprising:

first and second attachment ears attachable to the container wall, each of said ears having an aperture therein adapted to receive a rivet;

a lever portion having a lifting end and a rupturing section adjacent opposite ends, respectively, of said lever portion;

means for joining said attachment ears and said lever portion for pivotal movement of said lever portion about a hinge relative to said attachment ears, said attachment ears being remote from said lifting end and being on opposite sides of said rupturing see- On;

said tab being constructed of sheet material and having means for longitudinally stiffening said lever portion; and 7 said rupturing section being substantially at the periphery of the tab.

7. A tab as defined inclaim 6 wherein a marginal portion of the sheet material of said tab is turned to fonn a bead which extends around a major portion of the tab, said bead being discontinued at said hinge, said last mentioned means including at least a portion of said bead.

8. An easy opening container wall comprising:

a container wall of sheet material;

first, second and third rupturable lines of weakness on said container wall substantially intersecting at a region of intersection;

V first and second bendable lines of weakness extending substantially between the outer ends of said first and third rupturable lines of weakness and said second and third rupturable lines of weakness, respectively, said lines of weakness defining a tear portion;

a tab having an attachment portion and a lever portion joined together for pivotal movement of the lever portion relative to said attachment portion about a hinge, said lever portion having a rupturing region adapted to engage the tear portion and apply a force thereto;

means for attaching said attachment portion of said tab to said container wall outside of said tear portion with said rupturing region substantially overlying said region of intersection and being engageable therewith upon pivotal movement of said lever portion relative to said attachment portion to initiate severance of said rupturable lines of weakness; and

said lever portion having a lifting end remote from said rupturing region, said lifting end and the outer end of said third rupturable line of weakness being on the same side of said hinge.

9. An easy opening container wall as defined in claim 8 wherein said outer end of said third rupturable line of weakness lies radially outwardly relative to said region of intersection.

10. An easy opening container wall as defined in claim 8 wherein said tear portion is generally triangu: lar.

l 1. An easy opening container wall as defined in claim 8 wherein said attachment portion includes first and second attachment sections on opposite sides of said tear portion and said means for attaching independently attaches each of the attachment sections to the container wall.

12. An easy opening container wall comprising:

a container wall of sheet material;

a line of weakness in said container wall at least par tially defining a tear portion, said tear portion including a plurality of contiguous inwardly bendaopposite end; ble wall segments; a re ion of said tear rtion lyin on the side of said PO g a tab having an attachment portion joined to a lever axis opposite said opposite end and terminating at portion for pivotal movement of the lever portion a location remote from said axis, said region being relative to the attachment portion about a pivot forced inwardly by pivotal movement of said tab; axis, said lever portion having a lifting end, an end a opposite said lifting end, and a rupturing section the distance between said axis and said location adjacent said opposite end; being greater than said predetermined distance means for attaching said attachment portion to said whereby Pivofing of Said tab through approximatecontainer wall outside of said tear portion with one half p about $8161 8X15 does "0t said rupturing section substantially overlying a reclose Ofsald P gion of said tear portion so that pivotal movement An y p f comamer Y' a5 defined of the lever portion about said axis causes the rupclam? 12 wherein 531d tab can Plvoted h g P- turing Section to bear on the tear portion and proximately one half a revolution about said axis and mre Said line f weakness and f an Opening in 15 lies entirely within the area of the container wall. the container wall; 14. An easy opening container wall as defined in said axis extending across said tear portion and 'f 8 wherem rupmnng reg'on on the across the contiguous edges of said wall segments; penphery of said axis being a predetermined distance from said 

1. An easy opening container wall comprising: a container wall of sheet material; a line of weakness in said container wall at least partially defining a tear portion; a tab having an attachment portion joined to a lever portion for pivotal movement of the lever portion relative to the attachment portion, said lever portion having a rupturing section; and means for fixedly attaching said attachment portion to said container wall outside of said tear portion at first and second locations, said locations being on opposite sides of said tear portion,said rupturing section substantially overlying a region of said tear portion so that pivotal movement of the lever portion causes the rupturing section to bear on the tear portion and rupture said line of weakness.
 2. An easy opening container wall as defined in claim 1 wherein said lever portion is connected to said attachment portion along a hinge line and said hinge line extends across the tear portion.
 3. An easy Opening container wall as defined in claim 1 wherein said attachment portion includes first and second spaced attachment ears at said first and second locations, respectively.
 4. An easy opening container wall as defined in claim 1 wherein said rupturing section terminates in a rupturing point, said line of weakness includes first and second rupturable sections substantially intersecting at a point of intersection, and said rupturing point substantially overlies said point of intersection.
 5. An easy opening container wall comprising: a container wall of sheet material; a line of weakness in said container wall at least partially defining a tear portion; a tab having an attachment portion and a lever portion joined together for pivotal movement of the lever portion relative to said attachment portion about a hinge, said lever portion having a rupturing section adapted to engage the tear portion and apply a force thereto; and means for fixedly attaching said tab to said container wall outside of said tear portion with said hinge extending across a substantial segment of said tear portion, substantial segments of said tear portion lying on opposite sides of said hinge.
 6. A tab of the type attachable to a container wall comprising: first and second attachment ears attachable to the container wall, each of said ears having an aperture therein adapted to receive a rivet; a lever portion having a lifting end and a rupturing section adjacent opposite ends, respectively, of said lever portion; means for joining said attachment ears and said lever portion for pivotal movement of said lever portion about a hinge relative to said attachment ears, said attachment ears being remote from said lifting end and being on opposite sides of said rupturing section; said tab being constructed of sheet material and having means for longitudinally stiffening said lever portion; and said rupturing section being substantially at the periphery of the tab.
 7. A tab as defined in claim 6 wherein a marginal portion of the sheet material of said tab is turned to form a bead which extends around a major portion of the tab, said bead being discontinued at said hinge, said last mentioned means including at least a portion of said bead.
 8. An easy opening container wall comprising: a container wall of sheet material; first, second and third rupturable lines of weakness on said container wall substantially intersecting at a region of intersection; first and second bendable lines of weakness extending substantially between the outer ends of said first and third rupturable lines of weakness and said second and third rupturable lines of weakness, respectively, said lines of weakness defining a tear portion; a tab having an attachment portion and a lever portion joined together for pivotal movement of the lever portion relative to said attachment portion about a hinge, said lever portion having a rupturing region adapted to engage the tear portion and apply a force thereto; means for attaching said attachment portion of said tab to said container wall outside of said tear portion with said rupturing region substantially overlying said region of intersection and being engageable therewith upon pivotal movement of said lever portion relative to said attachment portion to initiate severance of said rupturable lines of weakness; and said lever portion having a lifting end remote from said rupturing region, said lifting end and the outer end of said third rupturable line of weakness being on the same side of said hinge.
 9. An easy opening container wall as defined in claim 8 wherein said outer end of said third rupturable line of weakness lies radially outwardly relative to said region of intersection.
 10. An easy opening container wall as defined in claim 8 wherein said tear portion is generally triangular.
 11. An easy opening container wall as defined in claim 8 wherein said attachment portion includes first and second attachment sections on opposite sides of said tear portion and said means for attaching independently attaches each of the attachment sections to the container wall.
 12. An easy opening container wall comprising: a container wall of sheet material; a line of weakness in said container wall at least partially defining a tear portion, said tear portion including a plurality of contiguous inwardly bendable wall segments; a tab having an attachment portion joined to a lever portion for pivotal movement of the lever portion relative to the attachment portion about a pivot axis, said lever portion having a lifting end, an end opposite said lifting end, and a rupturing section adjacent said opposite end; means for attaching said attachment portion to said container wall outside of said tear portion with said rupturing section substantially overlying a region of said tear portion so that pivotal movement of the lever portion about said axis causes the rupturing section to bear on the tear portion and rupture said line of weakness and form an opening in the container wall; said axis extending across said tear portion and across the contiguous edges of said wall segments; said axis being a predetermined distance from said opposite end; a region of said tear portion lying on the side of said axis opposite said opposite end and terminating at a location remote from said axis, said region being forced inwardly by pivotal movement of said tab; and the distance between said axis and said location being greater than said predetermined distance whereby pivoting of said tab through approximately one half a revolution about said axis does not close all of said opening.
 13. An easy opening container wall as defined in claim 12 wherein said tab can be pivoted through approximately one half a revolution about said axis and lies entirely within the area of the container wall.
 14. An easy opening container wall as defined in claim 8 wherein said rupturing region is on the periphery of the tab. 